Intra-cerebrospinal Fluid Research Articles

Evaluation of neuroretina following i.v. or intra-CSF AAV9 gene replacement in mice with MPS IIIA, a childhood dementia.

Sanfilippo syndrome (mucopolysaccharidosis type IIIA; MPS IIIA) is a childhood dementia caused by inherited mutations in the sulfamidase gene. At present, there is no treatment and children with classical disease generally die in their late teens. Intravenous or intra-cerebrospinal fluid (CSF) injection of AAV9-gene replacement is being examined in human clinical trials; evaluation of the impact on brain disease is an intense focus; however, MPS IIIA patients also experience profound, progressive photoreceptor loss, leading to night blindness. To compare the relative efficacy of the two therapeutic approaches on retinal degeneration in MPS IIIA mice. Neonatal mice received i.v. or intra-CSF AAV9-sulfamidase or vehicle and after 20 weeks, biochemical and histological evaluation of neuroretina integrity was carried out. Both treatments improved central retinal thickness; however, in peripheral retina, outer nuclear layer thickness and photoreceptor cell length were only significantly improved by i.v. gene replacement. Further, normalization of endo-lysosomal compartment size and microglial morphology was only observed following intravenous gene delivery. Confirmatory studies are needed in adult mice; however, these data indicate that i.v. AAV9-sulfamidase infusion leads to superior outcomes in neuroretina, and cerebrospinal fluid-delivered AAV9 may need to be supplemented with another therapeutic approach for optimal patient quality of life.

DDEL-10. RETROSPECTIVE REVIEW OF INTRA-CSF DRUG DELIVERY: SAFETY AND DRUG DISTRIBUTION PROFILES OF INTRACEREBROVENTRICULAR (ICV), LUMBAR INTRATHECAL (LIT), AND INTRA-CISTERNA MAGNA (ICM) INJECTIONS

Abstract INTRODUCTION The blood-brain barrier and blood-CSF barrier limit the uptake of CNS-targeted therapeutics. Given this limitation, intra-cerebrospinal fluid (CSF) drug delivery can be utilized. Here we review and compare thesafety and drug distribution of the different intra-CSF drug delivery methods. METHODS A retrospective literature review of the three most common CSF access methods (intracerebroventricular (ICV), lumbar intrathecal (LIT), and intra-cisterna magna (ICM)) was performed. The search consisted of human clinical trials published on PubMed from 2000 to present, with the following terms: intracerebroventricular/intraventricular/ICV, intrathecal/IT, cisterna magna/ICM/IT-CM, drug delivery, drug administration, and CSF. RESULTS The search yielded 34 ICV, 72 LIT, and 6 ICM studies. To investigate the safety and drug concentration profiles of each delivery method, we excluded studies reporting drug adverse events (AEs) rather than AEs related to the specific drug delivery method, leaving 21 ICV, 30 LIT, and 1 ICM studies, all of which spanned oncology and non-oncology treatment studies. ICV-specific safety was addressed in 10 ICV studies, with infection (N=6) and device malfunction (N=2) being among the most frequently mentioned device/procedure-associated AEs. LIT-specific safety was provided in 17 studies, with post-procedural headache (N=9), infection (N=5), and pain (N=5) being among the most mentioned AEs. For drug distribution, 42.9% (N=9) of ICV studies concluded that ICV delivery achieved sufficient drug exposure in the CNS for a meaningful therapeutic benefit, with drug concentrations reaching minimum effective doses and/or achieving high therapeutic indices. The single ICM study with infusion of bupivacaine for pain management did not analyze safety or drug distribution. Meanwhile, 30.0% (N=9) of LIT studies reached the same conclusion or achieved concentrations consistent with predicted values. CONCLUSION The safety profiles of both ICV and LIT injections are acceptable, showing mostly mild-to-moderate device/procedure-associated AEs. Additionally, ICV achieves therapeutic goals more consistently than the other intra-CSF delivery methods.

AAVrh10 vector corrects pathology in animal models of GM1 gangliosidosis and achieves widespread distribution in the CNS of nonhuman primates

GM1 gangliosidosis is a rare, inherited neurodegenerative disorder caused by mutations in the GLB1 gene, which encodes the lysosomal hydrolase acid β-galactosidase (β-gal). β-gal deficiency leads to toxic accumulation of GM1 ganglioside, predominantly in the central nervous system (CNS), resulting in progressive neurodegeneration. LYS-GM101 is an AAVrh.10-based gene therapy vector carrying the human GLB1 cDNA. The efficacy of intra-cerebrospinal fluid injection of LYS-GM101 analogs was demonstrated in GM1 mouse and cat models with widespread diffusion of β-gal and correction of GM1 ganglioside accumulation in the CNS without observable adverse effects. Clinical dose selection was performed, based on a good-laboratory-practice study, in nonhuman primates (NHPs) using the clinical LYS-GM101 vector. A broadly distributed increase of β-gal activity was observed in NHP brain 3 months after intra-cisterna magna injection of LYS-GM101 at 1.0×1012 vg/mL CSF and 4.0×1012 vg/mL CSF, with 20% and 60% increases compared with vehicle-treated animals, respectively. Histopathologic examination revealed asymptomatic adverse changes in the sensory pathways of the spinal cord and dorsal root ganglia in both sexes and at both doses. Taken as a whole, these pre-clinical data support the initiation of a clinical study with LYS-GM101 for the treatment of GM1 gangliosidosis.

Working Together to Accelerate the Preclinical to Clinical Translation of Drug Delivery Systems for Children’s Brain Tumours

Abstract AIMS Several techniques, such as intra-cerebrospinal fluid chemotherapy, ultrasound-mediated blood-brain barrier disruption, convection enhanced delivery, polymer delivery systems, electric field therapy, and intra-arterial and intra-nasal chemotherapy, have the potential to transform the treatment of brain tumours in children. However, there have been very few clinical trials to evaluate these. We aim to address challenges in the pre-clinical to clinical research pathway for CNS drug delivery systems in order to increase the number of clinical trials in this area. METHOD In 2021, the CBTDDC (Children’s Brain Tumour Drug Delivery Consortium) and the ITCC (Innovative Therapies for Children with Cancer) brain tumour group established a Clinical Trials Working Group comprising international researchers and clinicians to address this issue. RESULTS This partnership highlighted the main challenges as: (1) a lack of specific funding for prototype development and/or scale-up for clinical trials; (2) difficulties in navigating the regulatory landscape; (3) lack of accurate preclinical models; and (4) increased need for multi-centric working. In response to this, we ran a workshop on ‘Clinical Trial Readiness’, attended by around 50 delegates (comprising clinicians, researchers, trial regulatory experts, policy makers, and representatives from funding organisations, brain tumour charities and industry). CONCLUSION We have now established speciality-specific working groups with the aim of producing recommendations around the use of preclinical models and drug delivery techniques according to brain tumour type. We have also created a ‘Roadmap’ document for preclinical to clinical translation, which will be freely shared with the neuro-oncology research community.

EPCT-03. Working together to accelerate the preclinical to clinical translation of drug delivery systems for children’s brain tumours

Children's brain tumours are the biggest cancer killer in children and young adults. Several techniques, such as intra-cerebrospinal fluid chemotherapy, ultrasound-mediated blood-brain barrier disruption, convection enhanced delivery, polymer delivery systems, electric field therapy, and intra-arterial and intra-nasal chemotherapy, have the potential to transform the treatment of brain tumours in children. However, there have been very few clinical trials to evaluate these. In 2021, the CBTDDC (Children’s Brain Tumour Drug Delivery Consortium) and the ITCC (Innovative Therapies for Children with Cancer) brain tumour group established a Clinical Trials Working Group comprising international researchers and clinicians to address this issue. This partnership highlighted the main challenges in preclinical to clinical translation of paediatric CNS drug delivery as: (1) a lack of specific funding for prototype development and/or scale-up for clinical trials; (2) difficulties in navigating the regulatory landscape; (3) lack of accurate preclinical models; and (4) increased need for multi-centric working. In response to this, we ran a hybrid workshop in November 2021 on ‘Clinical Trial Readiness for CNS Drug Delivery’. At this workshop, around 50 delegates (comprising clinicians, researchers, trial regulatory experts, policy makers, and representatives from funding organisations, brain tumour charities and industry) came together to discuss issues around funding, preclinical models and regulatory processes. We have established speciality-specific working groups to build on the workshop discussions, with the aim of producing recommendations around the use of preclinical models and drug delivery techniques according to brain tumour type. We have also used the workshop presentations and discussions to create a ‘Roadmap’ document for preclinical to clinical translation, which will be freely shared with the neuro-oncology research community. We continue to liaise with funders and regulatory bodies to address the changes that are needed in these areas. If you would like to join our network, contact: cbtddc@nottingham.ac.uk

Lumboperitoneal Shunt Combined With Ommaya Reservoir Enables Continued Intraventricular Chemotherapy for Leptomeningeal Metastasis With Increased Intracranial Pressure.

Intra-cerebrospinal fluid (CSF) chemotherapy for leptomeningeal metastasis (LM) can be delivered intraventricularly via an Ommaya reservoir. However, hydrocephalus associated with LM can interfere with chemotherapeutic drug distribution, and ventriculoperitoneal shunts can prevent drug distribution to the extra-ventricular CSF space. This study examined the feasibility of combining a lumboperitoneal (LP) shunt with an Ommaya reservoir to both control intracranial pressure and allow for intraventricular chemotherapy. We identified 16 patients with LM who received both an Ommaya reservoir and an LP shunt, either concurrently or sequentially, and subsequently received intraventricular chemotherapy. The feasibility of this combination for intraventricular chemotherapy was evaluated by assessing 1) the distribution of intraventricularly injected drugs in CSF samples collected 0, 6, and 12 h post-injection and 2) adverse events associated with the procedure and drug administration. Patients received a median of seven rounds (range 1-37) of intraventricular chemotherapy during a median follow-up period of 5.2 months after LP shunt insertion. Pharmacokinetic data were obtained from six patients. Baseline methotrexate (MTX) levels from Ommaya reservoirs varied from 339.9 µM to 1,523.5 µM. CSF sampled from LP shunt reservoirs revealed an elimination half-life (t1/2) of 2.63 h, and the mean ratio of MTX concentration at 12 h to that at baseline was 0.05±0.05, ensuring drug distribution from the ventricle to the spinal canal. Nine patients (56%) underwent revision surgery due to catheter migration, malfunction, or infection. Among these patients, CSF infections attributable to intraventricular chemotherapy (n=3) occurred, but no infections occurred in later cases after we began to employ a complete aseptic technique. LP shunt combined with Ommaya reservoir insertion is a feasible option for achieving both intracranial pressure control and the continuation of intraventricular chemotherapy in patients with LM.

Abstract 1309: HSV1 oncolytic therapy for breast cancer meningeal metastases

Abstract Background: Meningeal metastasis is a fatal complication of breast cancer which results when cancer cells seed in the subarachnoid space. Subsequent tumor growth in the leptomeninges presents severe neurological complications of the cranial nerves, cerebrum and spinal cord limiting life expectancy to less than 4 months. Currently there is no cure. Aggressive multimodal therapies such as radiation, systemic and intra-cerebrospinal fluid (CSF) chemotherapy are ineffective. Chemotherapy is cleared rapidly from the CSF while doses deemed therapeutic are highly toxic. Oncolytic Herpes Simplex Virus type 1 (OHSV1) was selected as a potential therapeutic in this regard. Destruction of cancer cells by lytic virus replication is under clinical investigation where multiple virus replication cycles amplify the injected dose. We present OHSV1 therapeutics in a murine model of meningeal metastases where disease progression resembles that in the clinic. Methods: Meningeal metastases were induced in nude Balb/c mice by stereotaxic injection of MDA-MB-231 breast cancer cells into the right lateral ventricle of the brain. OHSV1 (1x10^8 pfu) was injected into the lateral ventricle on either day 9, 12 or 16 to target the early, intermediate and late disease phases of tumor growth in the model. Virus replication kinetics, tumor response, neurological and physical changes, and survival were studied for each treatment group. Virus replication was imaged with 18F-FHBG-PET and Fluc bioluminescence while tumor response to oncolytic HSV1 was imaged with Gd-MRI and Rluc-bioluminescence. The brains were studied ex vivo to confirm in vivo scans, virus with LacZ and antibody to viral TK, and titer with plaque assay. Results: A remarkable reduction metastatic growth to OHSV1 was evident in the early and intermediate groups where tumor growth was inhibited in some mice while existing tumors regressed in others. Tumor load in the base of the brain and spinal cord seen in control mice was markedly reduced in the two groups highlighted by minimal contrast uptake on Gd-MRI. As such the onset of neurological symptoms (bradykinesia, ataxia and paralysis) was delayed accompanied by weight gain. Inhibition of tumor growth in the late treatment group was relatively modest. Virus replication was evident as waves over the course of treatment in the three groups where the peaks represented virions released at the completion of a replication cycle. In vitro analyses correlated with in vivo observations. Early and intermediate OHSV1 therapy extended survival 12 and 7 days beyond the control group (day 21), while late OHSV1 therapy extended survival beyond 4 days. Conclusion: OHSV1 is therapeutic against life threatening disease progression when administered at early and intermediate stage disease with potential to target late stage disease. This treatment holds promise for breast cancer meningeal metastases that can be translated to the clinic. Citation Format: Darshini Kuruppu, Deepak Bhere, Khalid Shah, Anna-Liisa Brownell, Umar Mahmood, Kenneth K. Tanabe. HSV1 oncolytic therapy for breast cancer meningeal metastases [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1309.

AAV9-Mediated Expression of SMN Restricted to Neurons Does Not Rescue the Spinal Muscular Atrophy Phenotype in Mice

Spinal muscular atrophy (SMA) is a neuromuscular disease mainly caused by mutations or deletions in the survival of motor neuron 1 (SMN1) gene and characterized by the degeneration of motor neurons and progressive muscle weakness. A viable therapeutic approach for SMA patients is a gene replacement strategy that restores functional SMN expression using adeno-associated virus serotype 9 (AAV9) vectors. Currently, systemic or intra-cerebrospinal fluid (CSF) delivery of AAV9-SMN is being explored in clinical trials. In this study, we show that the postnatal delivery of an AAV9 that expresses SMN under the control of the neuron-specific promoter synapsin selectively targets neurons without inducing re-expression in the peripheral organs of SMA mice. However, this approach is less efficient in restoring the survival and neuromuscular functions of SMA mice than the systemic or intra-CSF delivery of an AAV9 in which SMN is placed under the control of a ubiquitous promoter. This study suggests that further efforts are needed to understand the extent to which SMN is required in neurons and peripheral organs for a successful therapeutic effect.

Intra-cerebrospinal fluid chemotherapy is new direction in pediatric solid tumors in developing countries

Introduction: Intra-cerebrospinal fluid (CSF) chemotherapy defined chemotherapy drugs administration in the brain/spine fluid compartment for leptomeningeal metastases treatment in infilterative tumors such as leukemia and lymphoma routinely. This method was administered for adults since 20 years ago but there is a limited experiences in children. Material and Method: We used electronic search on the online medical database "Pubmed" and other motor search-engines such as "Google Scholar” and selected all of articles about intra-CSF chemotherapy regimens in solid tumors. Results: We collected original articles and review articles over 20 years, on the target. All of selected articles include intratechal chemotherapy regimens in solid tumors in pediatrics and adult patients with leptomeningeal metastasis. Conclusion: We introduce several intra-CSF chemotherapy regimens in solid tumors.These approach can be used in pediatrics with radiation limitation.

Phase I feasibility study for intrathecal administration of trastuzumab in patients with HER2 positive breast carcinomatous meningitis

PurposeLeptomeningeal carcinomatosis (MC) is commonly associated with HER2-positive breast cancer (HER2-BC), with a poor prognosis and no standardised treatment. We conducted a phase I dose-escalation study of intrathecal (IT) administration of trastuzumab in HER2-BC patients with MC to determine the maximum tolerated dose (MTD), which was based on both the achievement of a trastuzumab intra-cerebrospinal fluid concentration close to a conventional therapeutic plasma concentration (30 mg/L) and/or dose-limiting toxicity (DLT). MethodsThe protocol planned IT administration of trastuzumab (30 mg, 60 mg, 100 mg or 150 mg dose levels) once a week, over the course of at least 4 weeks. Sixteen patients with MC from HER2-BC received IT trastuzumab. Intra-cerebrospinal fluid samples were obtained before each injection for pharmacokinetics. ResultsWe did not observe DLT of IT trastuzumab. Eleven patients had no toxicity attributed to IT trastuzumab. For 60 mg or higher dose levels, minor toxicities attributed to IT trastuzumab included headache (2 patients), nausea (2 patients), vomiting (1 patient), cervical pain (1 patient) and peripheral neuropathy (1 patient). Two patients experienced immediate toxicity including headache or vomiting. The mean residual intra-cerebrospinal fluid concentration of trastuzumab was 27.9 mg/L for the 150 mg dose level. Three patients achieved a clinical response, seven patients had stable disease and four patients had progressive disease. ConclusionsThe MTD and recommended phase II weekly dose of IT trastuzumab in patients with HER2-BC and MC is 150 mg. A phase II trial using this dose regimen in MC from HER2-BC is ongoing. Registration identificationClinicalTrials.gov Identifier: NCT01373710 (https://clinicaltrials.gov/ct2/show/NCT01373710?term=trastuzumab+intrathecal&rank=1).

Prognosis of leptomeningeal metastases from melanoma: A case series of 28 patients.

e13550 Background: Leptomeningeal metastasis (LM) are reported in 5-25% of patients with melanoma. However, only very few large contemporary cohorts of melanoma patients with LM have been published. Methods: We report on a case series of 28 consecutive patients with LM from melanoma (BRAF mutated in 14 cases, of 19 tested) diagnosed between April 2007 and April 2016, and treated for LM using a combination of systemic treatment, intra-cerebrospinal fluid (CSF) therapy and radiotherapy according to prior treatments and the presentation of LM. Results: The median age at LM diagnosis was 49.5 years (range 27-73). Median ECOG-performance status was 2 (0-4). Concomitant brain metastases were present in all but 4 patients at LM diagnosis. LM was the first site of metastatic disease for only 2 patients. Median time from melanoma diagnosis to LM diagnosis was 0.33 years in patients with metastatic disease at melanoma diagnosis (4 patients) and 4.5 years in patients without metastatic disease at melanoma diagnosis (24 patients). First line treatment for LM was a combination of intra-CSF (liposomal cytarabine) and systemic treatments in 25 cases, and systemic treatment alone in 3 cases. Systemic treatments include chemotherapy (n = 18), targeted therapy (BRAF inhibitor n = 9; MEK inhibitor, n = 3) and immunotherapy (n = 4). No radiotherapy was performed. Ten patients received more than one line of treatment for LM. Median progression-free survival with first line treatment was 1.75 months. Responses or stabilization (for at least 2 months) were observed in only 7 patients. Median overall survival (OS) for the whole cohort was 3.08 months. Conclusions: The prognosis of patients with LM from melanoma remains poor. The role of new agents such as targeted therapies and immunotherapy for the treatment of LM is still not well defined. Adequate use of intrathecal chemotherapy, targeted therapy and immunotherapy could improve the survival of these patients.

Leptomeningeal metastases in breast cancer patients — current rules of diagnosis and treatment

Leptomeningeal metastases (LM) presents a challenge because of the difficulty in determining the diagnosis and lack of optimal therapy. Nowadays, LM are more frequently diagnosed as a consequence of the long survival of patients with breast cancer and the improvement in image analysis. LM is a deleterious complication of breast cancer leading to death of patients within less than 3–6 months from the diagnosis. No generally accepted standard of care in the treatment of breast cancer LM exists. The treatment of patients with breast cancer and LM is of limited efficacy and substantial toxicity. Usually it requires focal radiotherapy to symptomatic sites or areas of bulky disease, intra-cerebrospinal fluid chemotherapy, or systemic intravenous/oral therapy, but the data regarding the sequence and efficacy of particular types of treatment are disputable. The management of breast cancer patients with LM was reviewed based on the data from literature. Additionally, the results of randomised clinical trials were reviewed.

Response of Leptomeningeal Dissemination of Anaplastic Glioma to Temozolomide: Experience of Two Cases.

The incidence of leptomeningeal dissemination (LMD) of anaplastic glioma has been increasing. LMD can be observed at the time of initial presentation or the time of recurrence. As a result of both rarity and unusual presentation, a standard therapy has not yet been suggested. In contrast to leptomeningeal carcinomatosis for systemic solid cancers, a relatively prolonged survival is observed in some patients with LMD of anaplastic gliomas. Treatment modalities include whole craniospinal irradiation, intra-cerebrospinal fluid (CSF) chemotherapy, and systemic chemotherapy. In some cases, response to temozolomide (TMZ), with or without combined radiation has been reported. Here, we report two cases of LMD of an anaplastic glioma. In one case LMD presented at the time of diagnosis, and in the other at the time of recurrence after radiation. CSF cytology was positive in both cases, and persisted in spite of intrathecal methotrexate chemotherapy. Later, TMZ was prescribed for progressing brain parenchymal lesions, and both radiological and cytological responses were obtained after oral TMZ treatment.

Slow, continuous enzyme replacement via spinal CSF in dogs with the paediatric-onset neurodegenerative disease, MPS IIIA.

Intra-cerebrospinal fluid (CSF) injection of recombinant human lysosomal enzyme is a potential treatment strategy for several neurodegenerative lysosomal storage disorders including Sanfilippo syndrome (Mucopolysaccharidosis type IIIA; MPS IIIA). Here we have utilised the MPS IIIA Huntaway dog model to compare the effectiveness of the repeated intermittent bolus injection strategy being used in the trials with an alternate approach; slow, continual infusion of replacement enzyme (recombinant human sulphamidase; rhSGSH) into the spinal CSF using a SynchroMed II® pump attached to a spinal infusion cannula. The ability of each enzyme delivery strategy to ameliorate lesions in MPS IIIA brain was determined in animals treated from ∼three- to six-months of age. Controls received buffer or no treatment. Significant reductions in heparan sulphate (primary substrate) were observed in brain samples from dogs treated via either cisternal or lumbar spinal CSF bolus injection methods and also in slow intra-spinal CSF infusion-treated dogs. The extent of the reduction differed regionally. Pump-delivered rhSGSH was less effective in reducing secondary substrate (GM3 ganglioside) in deeper aspects of cerebral cortex, and although near-amelioration of microglial activation was seen in superficial (but not deep) layers of cerebral cortex in both bolus enzyme-treated groups, pump-infusion of rhSGSH had little impact on microgliosis. While continual low-dose infusion of rhSGSH into MPS IIIA dog CSF reduces disease-based lesions in brain, it was not as efficacious as repeated cisternal or spinal CSF bolus infusion of rhSGSH over the time-frame of these experiments.

348. Correction of CNS and Somatic Pathology by Intra-Cerebrospinal Fluid Gene Therapy for Mucopolysaccharidosis Type II

Mucopolysaccharidosis type II (MPSII), or Hunter Syndrome, is a X-linked recessive Lysosomal Storage Disease (LSD) caused by deficiency in Iduronate-2-sulfatase (IDS), an enzyme involved in the stepwise degradation of the glycosaminoglycans (GAGs) heparan sulfate (HS) and dermatan sulfate (DS). GAG storage builds up in the CNS and peripheral tissues causing severe neurologic and multisystemic somatic disease. Patients usually die during the second decade of life. Periodic intravenous enzyme replacement therapy (ERT) currently constitutes the only approved therapeutic option for MPSII. However, the inability of recombinant IDS to efficiently cross the blood-brain barrier limits the efficacy of the approach in treating neurological symptoms. Alternatively, the periodic infusion of ERT to the cerebrospinal fluid is under clinical testing, but serious adverse events associated with the use of intrathecal drug delivery devices have been reported. Here we report a gene therapy approach directly addressing the CNS pathology of MPSII. Through a minimally invasive procedure we delivered adeno-associated virus vectors of serotype 9 encoding IDS (AAV9-Ids) to the CSF of MPSII mice with already established disease. Four months after vector administration, treated mice showed a significant increase in IDS activity throughout the encephalon, with full resolution of lysosomal storage lesions, reversal of lysosomal dysfunction, normalization of the brain transcriptomic signature and disappearance of neuroinflammation. Moreover, our approach not only resulted in widespread distribution of vector in the CNS but also in liver transduction, providing a peripheral source of therapeutic protein that corrected the storage disease in visceral organs, with evidence of cross-correction of non-transduced organs by circulating enzyme. Importantly, MPSII mice treated with AAV9-Ids also showed normalization of behavioural deficits. These results provide a strong proof of concept for the clinical translation of our approach for the treatment of Hunter patients with cognitive impairment.

Protease-resistant modified human β-hexosaminidase B ameliorates symptoms in GM2 gangliosidosis model.

GM2 gangliosidoses, including Tay-Sachs and Sandhoff diseases, are neurodegenerative lysosomal storage diseases that are caused by deficiency of β-hexosaminidase A, which comprises an αβ heterodimer. There are no effective treatments for these diseases; however, various strategies aimed at restoring β-hexosaminidase A have been explored. Here, we produced a modified human hexosaminidase subunit β (HexB), which we have termed mod2B, composed of homodimeric β subunits that contain amino acid sequences from the α subunit that confer GM2 ganglioside-degrading activity and protease resistance. We also developed fluorescent probes that allow visualization of endocytosis of mod2B via mannose 6-phosphate receptors and delivery of mod2B to lysosomes in GM2 gangliosidosis models. In addition, we applied imaging mass spectrometry to monitor efficacy of this approach in Sandhoff disease model mice. Following i.c.v. administration, mod2B was widely distributed and reduced accumulation of GM2, asialo-GM2, and bis(monoacylglycero)phosphate in brain regions including the hypothalamus, hippocampus, and cerebellum. Moreover, mod2B administration markedly improved motor dysfunction and a prolonged lifespan in Sandhoff disease mice. Together, the results of our study indicate that mod2B has potential for intracerebrospinal fluid enzyme replacement therapy and should be further explored as a gene therapy for GM2 gangliosidoses.

HSV-1 as a novel therapy for breast cancer meningeal metastases.

Meningeal metastasis is a fatal complication of breast cancer that affects 5-8% of patients. When cancer cells seed in the meninges, their subsequent growth results in severe neurological complications involving the cranial nerves, cerebrum and spinal cord, limiting life expectancy to less than 4 months. The incidences of meningeal metastases increase with prolonged lifespan resulting from treatment advances for primary breast cancer and their metastases. Currently, there is no cure. Aggressive multimodal therapies such as radiation and chemotherapy (intra-cerebrospinal fluid (CSF) and systemic) are ineffective. Therapeutic agents are often quickly cleared from the CSF, while higher doses that can achieve a therapeutic response are highly toxic. The secure guarding of the subarachnoid space by the blood-brain barrier on one side and the blood-CSF barrier on the other prevents chemotherapy from reaching cancer cells in the meninges. These challenges with treating meningeal metastases highlight the urgent need for a new therapeutic modality. An ideal treatment would be an agent that avoids rapid clearance, remains within the CSF, reaches the meninges and selectively destroys tumor cells. Replication conditional oncolytic herpes simplex virus type 1 (HSV-1) may be effective in this regard. Viral oncolysis, the destruction of cancer cells by replicating virus, is under clinical investigation for cancers that are unresponsive to current therapies. It is based on the model of multiple cycles of lytic virus replication in cancer cells that amplify the injected dose. The therapeutic potential of oncolytic HSV-1 for breast cancer meningeal metastases is discussed here. HSV-1 could be a potential novel treatment for meningeal metastases that can be translated to the clinic.

Safety of intra-cerebrospinal fluid chemotherapy in onco-haematological patients: a retrospective analysis of 627 interventions.

Intra-cerebrospinal fluid chemotherapy (ICC) is used widely to treat or prevent neoplastic meningitis (NM), although its safety has not been thoroughly assessed. We aimed to analyse the incidence, severity and cause of the adverse reactions provoked by ICC in a cohort of onco-haematological patients. We retrospectively reviewed all the adverse reactions related to ICC procedures performed by the same researcher over a 5-year period. We classified them according to their severity and cause, and examined their association with certain characteristics of the patients and interventions. A total of 627 procedures were performed on 124 patients, in which 59 adverse reactions were documented (9.4 %). Thirty-two (54 %) of these were considered severe and 30 (51 %) were due to the drug itself. NM was associated with a higher incidence of adverse reactions (p = 0.002) and severe adverse reactions (p < 0.001). Adverse reactions were more common (p = 0.028) and more often severe (p = 0.008) when an Ommaya reservoir was used, as opposed to the lumbar puncture procedure. The use of liposomal cytarabine was also associated with a higher incidence of adverse reactions (p < 0.001) and serious adverse reactions (p < 0.001) than immediate-release drugs. Liposomal cytarabine provoked more adverse reactions attributable to the drug when administered by lumbar puncture (p = 0.192), whereas the remaining drugs had higher risk when administered via Ommaya reservoir (p = 0.015). ICC seems a relatively safe procedure. Adverse reactions appear to be more frequent when NM is already present. Lumbar puncture seems to be safer than the Ommaya reservoir, except when liposomal cytarabine is administered.

Determination of the role of injection site on the efficacy of intra-CSF enzyme replacement therapy in MPS IIIA mice.

MPS IIIA is an inherited neurodegenerative lysosomal storage disorder characterized by cognitive impairment, sleep-wake cycle disturbance, speech difficulties, eventual mental regression and early death. Neuropathological changes include accumulation of heparan sulfate and glycolipids, neuroinflammation and degeneration. Pre-clinical animal studies indicate that replacement of the deficient enzyme, sulfamidase, via intra-cerebrospinal fluid (CSF) injection is a clinically-relevant treatment approach, reducing neuropathological changes and improving symptoms. Given that there are several routes of administration of enzyme into the CSF (intrathecal lumbar, cisternal and ventricular), determining the effectiveness of each injection strategy is crucial in order to provide the best outcome for patients. We delivered recombinant human sulfamidase (rhSGSH) to a congenic mouse model of MPS IIIA via each of the three routes. Mice were euthanized 24h or one-week post-injection; the distribution of enzyme within the brain and spinal cord parenchyma was investigated, and the impact on primary substrate levels and other pathological lesions determined. Both ventricular and cisternal injection of rhSGSH enable enzyme delivery to brain and spinal cord regions, with the former mediating large, statistically significant decreases in substrate levels and reducing microglial activation. The single lumbar CSF infusion permitted more restricted enzyme delivery, with no reduction in substrate levels and little change in other disease-related lesions in brain tissue. While the ventricular route is the most invasive of the three methods, this strategy may enable the widest distribution of enzyme within the brain, and thus requires further exploration.

Recent Advancements of Treatment for Leptomeningeal Carcinomatosis.

Treatment of Leptomeningeal carcinomatosis (LMC) from solid cancers has not advanced noticeably since the introduction of intra-cerebrospinal fluid (CSF) chemotherapy in the 1970's. The marginal survival benefit and difficulty of intrathecal chemotherapy injection has hindered its wide spread use. Even after the introduction of intraventricular chemotherapy with Ommaya reservoir, frequent development of CSF flow disturbance, manifested as increased intracranial pressure (ICP), made injected drug to be distributed unevenly and thus, the therapy became ineffective. Systemic chemotherapy for LMC has been limited as effective CSF concentration can hardly be achieved except high dose methotrexate (MTX) intravenous administration. However, the introduction of small molecular weight target inhibitors for primary cancer treatment has changed the old concept of 'blood-brain barrier' as the ultimate barrier to systemically administered drugs. Conventional oral administration achieves an effective concentration at the nanomolar level. Furthermore, many studies report that a combined treatment of target inhibitor and intra-CSF chemotherapy significantly prolongs patient survival. Ventriculolumbar perfusion (VLP) chemotherapy has sought to increase drug delivery to the subarachnoid CSF space even in patients with disturbed CSF flow. Recently authors performed phase 1 and 2 clinical trial of VLP chemotherapy with MTX, and 3/4th of patients with increased ICP got controlled ICP and the survival was prolonged. Further trials are required with newly available drugs for CSF chemotherapy. Additionally, new LMC biologic/pharmacodynamic markers for early diagnosis and monitoring of the treatment response are to be identified with the help of advanced molecular biology techniques.